Stunning device for killing small animals or fish

ABSTRACT

Stunning device ( 1 ) for small animals or fish of 2kg to 7kg weight comprises pneumatically powered piston assembly ( 2 ) which includes an extendible piston. Support ( 3 ) for piston assembly ( 2 ) includes base member ( 4 ) and multi-component trigger ( 22, 23, 24, 26 ). Piston assembly ( 2 ) is positioned to define a space between base member ( 4 ) and head plate ( 21 ) for receiving the head ( 27 ) of the animal. When the piston is activated by head ( 27 ) contacting plate ( 22 ), it extends and strikes head ( 27 ) just behind and/or between the eyes with sufficient force to kill the animal with a shock to the brain, but without affecting the external appearance of the animal or fish. The piston extends only once and then retracts, and trigger ( 22, 23, 24, 26 ) is reset by removing head ( 27 ) from device ( 1 ).

[0001] This invention relates to apparatus which can be used to stun, orslaughter, small animals and fish. In particular, the invention relatesto pneumatically operated apparatus.

BACKGROUND FIELD

[0002] Processing of animals for food usually involves the initialslaughter of the animal. In the processing of larger animals such ascattle, this is typically done by a blow to an animal's head using apneumatically- or cartridge-powered gun with a captive bolt or piston inplace of a projectile.

[0003] Processing of some fishes also requires slaughter as an initialstep in the process. For example, salmon are typically “stunned” by ablow to the head before processing as food. In many instances, the blowis applied with a simple club, there being no readily availableapparatus for the procedure. Smaller animals such as rabbits aresimilarly stunned by a blow to the head, there again being no readilyavailable apparatus suitable for use with animals of this size.

[0004] Any apparatus must be capable of delivering a blow to the head ofan animal or fish in such a way that stunning can be done humanely. Formost processing needs, the apparatus must also be capable of deliveringblows quickly and repetitively so that large numbers of animals or fishcan be processed.

[0005] Pneumatically powered apparatus is used for larger animalsbecause it meets the needs set out in the previous paragraph. However,such apparatus is not suitable for use with smaller animals or fish.Smaller hand-held pneumatic devices are known-for example, pneumaticallypowered nail guns-but these are not suitable for use as a fish or animalstunning device because of their configurations. Such devices arenevertheless capable of delivering an adequate force.

SUMMARY OF THE INVENTION

[0006] The object of the invention is to provide a stunning device thatcan be used for the rapid and repetitive stunning of small animals orfish and that utilizes pneumatic power.

[0007] In a broad format, the invention provides an animal or fishstunning device comprising:

[0008] a pneumatically-powered piston assembly comprising a pistonretractably extendable from an open ended cylinder included in saidassembly;

[0009] a support for said piston assembly including a base member,wherein said piston assembly is positioned with respect to said basemember to define a space between said base member and said cylinder openend for receiving a head of an animal or fish, and wherein said pistoncan extend partially into said space; and

[0010] a trigger for activating extension of said piston when saidtrigger is contacted by the head of said animal or fish when positionedin said space.

[0011] The operating principle of the stunning device according to theinvention is that that the animal or fish is killed by a blow to thehead administered by the piston of the device. The action is initiatedby insertion of the animal's or fish's head into the space between thebase member of the support for the piston assembly and the open end ofthe cylinder whereby contact with a trigger activates the piston. Thetrigger and cylinder are configured such that when the piston isactivated, it strikes the animal or fish just behind and/or between theeyes. This impact is sufficient to kill the animal or fish due to theshock to the brain.

[0012] A design feature of the device is that when activated, the pistonextends only once and then retracts. Removal of the animal or fishresets the trigger so that the device can be immediately used to stunanother animal or fish.

[0013] The piston assembly of devices according to the invention isadvantageously pivotally mounted to the support so that the distancebetween the base member and the open end of the cylinder can be adjustedto allow use with differently sized animals and fishes. The pistonassembly can be either fixed in a particular position or mounted suchthat some degree of movement is possible. This allows for automaticadjustment of the distance between the base member and the open end ofthe cylinder when differently sized individuals of the same species ofanimal or fish are to be slaughtered.

[0014] The mounting of the piston assembly to the support is typicallysuch that the assembly can be demounted to allow cleaning of bothcomponents. Devices advantageously include guide plates to facilitateinsertion of the head of the animal or fish into the space between thebase member of the support and the open end of the cylinder. Preferably,the distance between guide plates at each side of the entrance to thedevice is adjustable. Advantageously, the entire device can bedismantled for cleaning of all components.

[0015] The support for the piston assembly advantageously comprises aplanar base member and planar side members. Alternatively, the supportcan be a framework of elongate members.

[0016] The pneumatic operation of the piston is typically effected byincorporating apparatus commonly known as a “nail gun” in the pistonassembly of devices according to the invention. As such guns aretypically capable of repetitive firing on activation, devices include amechanism which allows only a single extension of the piston. This willbe explained in greater detail below. However, it will be appreciated byone of skill in the art of the manufacture of such devices that thepneumatically-operated piston can be any suitable assembly including apurpose-built assembly.

[0017] Devices according to the invention can be used with small animalsand are particularly suited for use with animals having a weight of 2 to7 kg. With regard to fishes, devices can be conveniently used with fishhaving a weight of up to about 7 kg such as salmon, trout and sea bass.Devices are most particularly suited for the stunning of salmon duringthe commercial processing thereof.

[0018] With devices according to the invention, animals or fish to beprocessed can be rapidly and efficiently stunned with minimal risk ofinjury to the operator. Furthermore, as triggering is effected by thehead of the animal or fish, both hands of the operator can be used toguide the head of the animal or fish into the device. An additionaladvantage of devices according to the invention is that the externalappearance of the animal or fish is not affected by the killing process.This is particularly important for sale of whole fish. The quality offish is also enhanced through more rapid and humane killing at the pointof harvest.

[0019] Having broadly described the invention, stunning devices will nowbe exemplified with reference to the drawings briefly describedhereafter.

BRIEF DESCRIPTION OF THE DRAWINGS

[0020]FIG. 1 is a perspective view of a device according to theinvention.

[0021]FIG. 2 is a side view of the device shown in FIG. 1 with portionsof the support for the piston assembly omitted.

[0022]FIG. 3 is a side view of another device according to the inventionwith a side member of a support assembly omitted to expose features ofthe device.

[0023]FIG. 4 is a side view of the support assembly of the device shownin FIG. 3 with components omitted to expose adjustment and releasemechanisms.

[0024]FIG. 5 is a detailed view of the adjustable mounting for a guideplate.

[0025] The same item number has been used for features appearing in morethan one drawing.

BEST MODE AND OTHER MODES OF CARRYING OUT THE INVENTION

[0026] The devices depicted in the figures are designed for the stunningof adult salmon in the commercial processing thereof. However, it willbe appreciated that with appropriate reconfiguration, the device can beadapted for use with other fishes or animals.

[0027] In FIGS. 1 and 2, there is shown device 1 comprising pistonassembly 2 and support assembly 3. To first deal with the supportassembly, this comprises a planar base member 4 and planar side members5 and 6 linked by a cross-piece 7. In FIG. 2, side member 6 has beenomitted so that other features of the device can be seen. Supportassembly 3 further includes guide plates 8 and 9 that are adjustablyfixed to side members 5 and 6, respectively. Taking guide plate 9 as anexample, fixing is via a shaft 10 extending from an end of the guideplate, which shaft can be locked—typically via a threaded stud—into acollar 11 on side member 6. Base member 4 has fixed thereto a chin plate12 which aids proper positioning of the head of the fish in the deviceas will be explained below.

[0028] Turning to piston assembly 2, this is pivotally mounted to anaxle 13 extending between side members 5 and 16 to which rails at eachside of the assembly are connected. One of these rails is item 14 ofFIG. 2 which is the rail furthest the viewer. The rail at the other sideof the piston assembly has been omitted to again allow features of theassembly to be seen. Pivoting of piston assembly 2 is limited inmovement away from base member 4 by adjusting screw 15 in cross-piece 7which contacts a tab 16 extending from the assembly. The minimumdistance between open ended cylinder 17 from which the piston of thepiston assembly extends and chin plate 12 is set by an adjusting screw18 on the piston assembly which contacts a tab 19 projecting inwardlyfrom side member 6. Adjusting screw 18 and tab 19 are shown in phantomin FIG. 2. It will be appreciated from FIG. 2 that with adjusting screws15 and 18 set as shown, some pivoting of piston assembly 2 is stillpossible. That is, the piston assembly can pivot until tab 16 contactsthe end of adjusting screw 15. This allows adjustment of the distancebetween cylinder 17 and chin plate 12 to compensate for differentlysized fish.

[0029] Cylinder 17 is essentially a sleeve mounted to a standardpneumatic gun 20, the particular gun in the example being a Max ModelNo. NF510 manufactured by Max Co., Ltd, Tokyo, Japan. The cylinder boreis indicated by the dashed lines in FIG. 2. The normal piston of the gunis replaced with a sealed hollow stainless steel cylinder of about 100mm in length. The end of the piston that extends from the cylinder has aconvex curvature to minimise damage to fish to be stunned which couldoccur with a piston having a flat extremity. The cylinder has mounted atits open end a head plate 21, with an appropriate aperture therein toallow passage of the piston, to further aid positioning of a fish in thedevice.

[0030] The trigger of device I comprises a contact plate 22 adjustablylinked to a pivot frame 23 which has a pushrod 24 extending therefromfor contacting the activating button 25 of pneumatic gun 20. Pushrod 24is also acted on by a pneumatic pushrod 26 that disengages pushrod 24from button 25 during operation of the device. This will be explainedbelow. The position of contact plate 22 relative to the head 27 of afish positioned in the device can be set by adjusting the angle betweenthe contact plate and pivot frame 23 via adjusting screw 28. Pivot frame23 is biased to a pre-firing position as shown in FIG. 2 by spring 29with the position adjustable via a stop screw 30. The movement ofpushrod 24 is limited by a stop screw 31 and the pushrod is biased tothe button 25 contact position shown in FIG. 2 via spring 32. The pistonassembly also includes a five-way valve 33, the function of which willbe described below.

[0031] Device components such as the support assembly 3 are typicallyfabricated from a corrosion resistant metals material. A preferredmaterial is stainless steel. The support assembly of the exemplifieddevice has a length of about 370 mm, a width of about 185 mm, and aheight of about 205 mm. The pneumatic nail gun component 20 of thepiston assembly utilizes a normal air supply of 3.0 to 5.0 bar andtypically operates at 3.5 bar. The device is suitable for stunning fishsuch as salmon of 2 to 7 kg.

[0032] Operation of device 1 will now be described. To stun a fish, thehead 27 thereof is positioned in the space between head plate 21 andchin plate 12 aided by guide plates 8 and 9. Movement of fish head 27further into this space ultimately results in the nose 34 of the fishmeeting contact plate 22 which causes pushrod 31 to depress button 25 ofpneumatic gun 20. The piston then extends from cylinder 17 by up toabout 30 mm thereby contacting the head of the fish. To prevent multiplefiring of the gun (which would result in excessive damage to the fish),pushrod 24 is stopped by stop screw 31 so that depression of button 25is only to an initial (single fire) position. To allow immediateretraction of the piston, pushrod 24 is disengaged from button 25 bypneumatic pushrod 26. The latter pushrod is activated by five-way valve33 which senses a drop of pressure on firing of the gun to extend thepiston with air being diverted to the pushrod. On removal of the stunnedfish, contact plate 22 and pushrod 24 are returned to the positionsshown in FIG. 2 under the action of springs 29, and 32, respectively.

[0033] The device is then ready for repetition of the foregoingprocedure.

[0034] Device 1 is typically fixed to a horizontal surface, such as abench top, for use. However, it will be appreciated that the device canbe used in any orientation.

[0035] In a variant of the device exemplified above, the pneumaticpushrod 26 and five-way valve 33 can be replaced by a spring-extendeddouble acting cylinder arrangement, thus avoiding the need for thefive-way valve.

[0036] A variant of the device shown in FIGS. 1 and 2 is depicted inFIGS. 3 and 4. With reference to FIG. 3, there is shown device 35comprising piston assembly 36 and support assembly 37. The supportassembly 37 is essentially the same as support assembly 3 of the devicedescribed above. Differences will be discussed below.

[0037] The piston assembly 36 includes a standard pneumatic gun 38 whichin this case is a Max Model No. NF352-ST/16-50 obtainable from Max Co.,Ltd, Tokyo, Japan. As this gun has a shorter barrel than the gun used inthe FIGS. 1 and 2 device, a sleeve 39 is mounted between gun 38 andcylinder 40, which cylinder 40 is similar to cylinder 17 of the FIGS. 1and 2 device. In the present case, the piston within cylinder 40 issolid and is connected to the piston of gun 38 by a solid rod not shownin the figure. The piston is grooved at its upper end, which groove hasan o-ring therein. The o-ring prevents slippage of the piston in betweenfirings of the gun. These details are again not shown in the figure.

[0038] The trigger mechanism of device 35, and the operation thereof, isthe same as the trigger mechanism of the FIG. 1 and 2 device. Onedifference in the operation of the gun, however, is that there is asupply of air to the body of gun 38 which air acts on the underside ofthe gun piston to aid retraction of the piston after firing. This supplyof air is from a branch line 41 of the air line 42 from five-way valve43 to the pushrod 44 that is the equivalent of pushrod 26 of the FIGS. 1and 2 device. Consequently, after the gun is fired, there is a momentarysupply of air through line 42 and hence then to the gun body via line 41to aid cylinder retraction.

[0039] Device 35 further includes a pressure relieve valve 43 a whichreceives air from a compressor. The device typically operates at 5.0bar.

[0040] Device 35 also has a cover, shown in phantom as 45 in FIG. 3,secured to support assembly 37 by a spring clip on each side of thedevice, one of which spring clips is shown at 46. The device has twoguide plates like those of the FIGS. 1 and 2 device but of the samelength. One of the guide plates, 47 of FIG. 3, is hinged at itsmid-point 48 with the distal half 49 biased away from the centre of thedevice. When the device is mounted close to a wall with guide plate 47on the side of the device closest the wall, the distal half 49 willcontact the wall thereby closing any gap between the device and thewall. This prevents a fish entering the gap between the device and thewall. The distance between the guide plates can be adjusted by theindependent setting of each plate by a mechanism to be explained indetail below.

[0041] The angle of chin plate 50 of device 35 can be adjusted. The chinplate is pivotally mounted to the base 51 of support assembly 37 at 52.A spring-loaded pin at the distal end of the chin plate is received inone of the notches in a notched plate 53 on a side wall of the supportassembly.

[0042] Greater detail of adjustment mechanisms is presented in FIGS. 4and 5. In FIG. 4, there is shown the base member 51 and a side member 54of support assembly 37. A support rail 55 for gun 38 is pivotallymounted at 56 to side member 54. The position of the gun is adjustableby virtue of adjusting screw 57.

[0043] To aid cleaning of the device, piston assembly 36 can be pivotedout of support assembly 37 once cover 45 has been removed. To allowthis, a boss 58 at the end of adjusting screw 57 can be released from aclasp 59 therefor by virtue of a lever 60 acted on by an over-centrespring which normally retains the clasp about boss 58.

[0044] Adjusting screw 57 is adjacent side wall 54. The upper end of thescrew has a tee-piece 61. This tee-piece cannot rotate when theadjusting screw is locked in position and cover 45 is in situ.Consequently, movement generated by operation of gun 38 does not alterthe setting of rail 55 and hence the position of cylinder 40 relative tobase member 51 (see FIG. 3).

[0045] When lever 60 is in the released position-which can only occurwhen cover 45 is removed—the lever lies across spring clip 62, thecomplement of spring clip 46 of FIG. 3. Consequently, the cover cannotbe refitted. This prevents use of the device when adjusting screw 57 isnot properly latched. Spring clips 46 and 62 can be interlinked so thatblocking of only one clip prevents operation of both clips.

[0046] A mechanism for the adjustable mounting of a guide plate to sidemember 54 is shown at 63 of FIG. 4 and in more detail in FIG. 5, thelatter being an exploded view. FIG. 5 shows a shaft 64 which projectsfrom the end of the guide plate within the support assembly (see FIG.3). This shaft is received in a boss 65 on a side wall of the supportassembly. Shaft 64 includes a plurality of grooves 66 into one of whicha spring loaded plate 67 can drop when the shaft is in boss 65. Thislocks shaft 64 in a particular position and thus sets the position ofthe attached guide plate relative to the side walls of the supportassembly. Lifting plate 67 via tab 68 allows repositioning of the shaftand hence the guide plate.

[0047] The device illustrated in FIG. 3 is operated in the same manneras the FIGS. 1 and 2 device.

[0048] It will be appreciated that many changes can be made to thestunning devices and use thereof as exemplified above without departingfrom the broad ambit and scope of the invention.

[0049] The term “comprise”, or variants thereof such as “comprising” or“comprised”, is used herein to denote the inclusion of a stated integeror integers, unless is the context of usage an exclusive interpretationof the term is required.

1. An animal or fish stunning device comprising: a pneumatically-poweredpiston assembly comprising a piston retractably extendable from an openended cylinder included in said assembly; a support for said pistonassembly including a base member, wherein said piston assembly ispositioned with respect to said base member to define a space betweensaid base member and said cylinder open end for receiving a head of ananimal or fish, and wherein said piston can extend partially into saidspace; and a trigger for activating extension of said piston when saidtrigger is contacted by the head of said animal or fish when positionedin said space, wherein said trigger includes a mechanism for preventingrefiring of said piston while said head of said animal or fish is incontact with said trigger.
 2. The device according to claim 1, whereinsaid piston assembly is pivotally mounted to said support.
 3. The deviceaccording to claim 2, wherein an adjustment mechanism is provided tolimit pivoting of said piston assembly or to fix said piston assemblyinto a desired position relative to said base member.
 4. The deviceaccording to claim 3, wherein said adjustment mechanism comprises screwsthat abut tabs projecting from said piston assembly mounting or saidsupport therefor.
 5. The device according to claim 3, wherein saidadjustment mechanism comprises an adjusting screw on said pistonassembly support that engages a threaded boss on said support.
 6. Thedevice according to claim 5, wherein said boss can be disconnected fromsaid support to permit pivoting of said piston assembly out of saidsupport.
 7. The device according to claim 6, wherein said boss isconnected to said support via a clasp that can be opened for pivoting ofsaid piston assembly.
 8. The device according to claim 7, whereinopening of said clasp is via a lever acted on by an over-centre springthat normally holds said clasp closed.
 9. The device according to claim1, wherein mounting of said piston assembly to said support is via apair of parallel rails pivotally connected at an end of each rail tosaid support.
 10. The device according to claim 9, wherein said pivotalconnection is via an axle spanning said support.
 11. The deviceaccording to claim 1, wherein said support comprises a planar basemember and planar side members.
 12. The device according to claim 1,wherein an upright guide plate is provided at each side of side supportat said space defined by said base member and said cylinder open end.13. The device according to claim 12, wherein each said guide plate isadjustably mounted to said support for varying the distancetherebetween.
 14. The device according to claim 13, wherein saidadjustable mounting comprises a shaft extending from a guide plate thatis received in a boss on said support and is locked into position by athreaded stud in said-boss.
 15. The device according to claim 13,wherein said adjustable mounting comprises an annularly grooved shaftextending from a guide plate that is received in a boss on said supportand is held in position by a backing plate that docks in a groove. 16.The device according to claim 12, wherein a distal portion of at leastone of said guide plates is hinged and biased away from said device. 17.The device according to claim 1, wherein said base member has a rampedmember in said space that acts as a chin plate.
 18. The device accordingto claim 17, wherein the slope of said ramped member is adjustable. 19.The device according to claim 1, wherein said piston assembly comprisesa pneumatic gun with a sleeve as said cylinder.
 20. The device accordingto claim 19, wherein a spacer sleeve is positioned between-said cylinderand said gun body.
 21. The device according to claim 19, wherein saidtrigger comprises: a contact plate adjustably linked to a pivot framehaving a first pushrod extending therefrom for contacting an activatingbutton of said gun; and a second, pneumatically operated, pushrod thatdisengages said first pushrod from said button immediately afteractivation of said button; wherein said pivot frame is biased to apre-firing position and said first pushrod is biased towards saidbutton.
 22. The device according to claim 1, wherein said deviceincludes a multiple-outlet valve for controlling supply of air to devicecomponents.
 23. The device according to claim 19, wherein an air linefrom a multiple-outlet valve is connected to said gun body to supply airto the underside of said gun piston to aid retraction of said cylinderpiston after firing of said gun.
 24. The device according to claim 1,wherein said piston includes an o-ring seal to prevent slippage of saidpiston after retraction thereof.
 25. The device according to claim 1,wherein a cover is provided over said device with an opening thereinthat coincides with the space between said base member and said cylinderopen end.
 26. The device according to claim 25, which further includes amechanism that prevents activation of said device when said cover isabsent.
 27. The device according to claim 1, wherein a plate is providedthat extends outwardly of the periphery of the open end of saidcylinder.
 28. An animal or fish stunning device comprising: an assemblycomprising a pneumatic gun connected to a piston within an open-endedcylinder, the gun being mounted to a frame comprising parallel rails; asupport into which said assembly is pivotally fitted via said rails, thesupport comprising a planar base member and planar side members, whereinsaid assembly is positioned with respect to said base member to define aspace between said base member and said cylinder open end for receivinga head of an animal or fish, and wherein said piston can extendpartially into said space; and a trigger for activating extension ofsaid piston when said trigger is contacted by the head of said animal orfish when positioned in said space, said trigger comprising a contactplate that is adjustably linked to a pivot frame having a first pushrodextending therefrom for contacting an activating button of said gun; anda second, pneumatically operated, pushrod that disengages said firstpushrod from said button immediately after activation of said button toprevent refiring of said piston while said head of said animal or fishis in contact with said trigger; wherein said pivot frame is biased to apre-firing position and said first pushrod is biased towards saidbutton.